Exporting in Hitfilm Express 2017

After downloading and activating Hitfilm Express 2017 I'm unable to use any of the pre-sets for exporting. All of the pre-sets are showing a locked padlock and although the program goes through the motions of exporting a project in MP4 format, the saved project shows only a black screen when played back. The only export function which seems to work is to save as AVI format. Any help to resolve this would be very much appreciated.

Hitfilm Express 2017 is my first editor and have only had it as of May 25th, downloaded it free. Of the work I've already done, it seems as though I can't export it properly. I get an MP4 file with only audio and no visuals.

I receive the following messages no matter the preset I choose:

GL_INVALID_OPERATION - The specified operation is not allowed in the current state.

The offending command is ignored and has no other side effect than to set the error flag.

@Ffnetnut These are the settings for your graphics card drivers. I assumed that you had a dedicated GPU but I might have spoken too hastily, do you know what graphics card you have? Could you give us more details about your machine please?

@Ffnetnut You need to use the Nvidia control panel to force HitFilmRenderClient.exe to use your 720m GPU instead of the HD 4000. To do that right click on your Desktop and select Nvidia Control Panel

Once it opens look under 3D settings on the left hand side and select Manage 3D Settings.

Go to the Program Settings tab. There will be a drop down list of programs under Select a Program to Customize: but the one you need to customize, HitFilmRenderClient.exe won't be in it so you'll have to click Add and browse to where you have HitFilm installed to find HitFilmRenderClient.exe and add it to the list. Once it's added, select it.

Now you can select the preferred GPU under Select the preferred graphics processor for this program. Select the Nvidia entry and you should be good to go.